The Mute Swan is a beautiful bird, which is the main reason there is such a large, feral population in the US. It is a big bird, with cobs (males) weighing as much as 26, and the slightly smaller pens (females) weighing around 20 pounds. In fact, Mute Swans are one of the heaviest flying birds in the world.
With the longest necks of any swan species, and generally large bodies, Black Swans are striking in appearance discounting their plumage. They are almost all black but do have white flight feathers on their wings. They have red bills that have a distinct white band around them. Their legs and feet are grayish-black.